6 October 2018 – Postal Codes 50 Years
The purpose of introducing postal codes in Norway was so it would be easier to sort the mail manually. Previously, this job had required extremely good knowledge about geography.
Another benefit of postal codes was optic readability; it became possible to sort mail by machine using OCR (Optical Character Recognition).
Letter-sorting machines with this technology arrived in the late 1970s. The machines made it possible to sort the mail automatically by postal code.
As computers became more powerful, more and more mail could be scanned using OCR. Over time the system also began to read street addresses.
Four-digit postal codes were introduced in Norway on 18 March 1968. The exception was Oslo, which used zone numbers instead (Oslo 1, Oslo 2, etc.). On 1 April 1984, the country's capital was also assigned four-digit postal codes.